CHICAGO - A fire apparently set by an employee at a Chicago-area air traffic control center led to the cancellation of more than 1,700 flights at the city's two major airports, snarling air traffic across the United States, officials said.
Flights resumed at O'Hare International Airport
, one of the world's busiest, after a delay of about four hours, but there were bottlenecks across the entire air system that carriers expect to last through the weekend.
The blaze at the facility in Aurora, near Chicago
, appeared to be set by a man who suffered self-inflicted knife wounds, Aurora police
said. There were no indications that it was an act of terrorism and the blaze was quickly extinguished, they said.
The fire was set by a longtime employee of Harris Corp , which provides equipment and technical support for the Federal Aviation Administration facility
and many others, US government
officials said. The name of the employee has not been released.